The present disclosure relates generally to gaming machines and wagering and, more particularly, to a gaming machine that includes a brushless motor system for improving operations of the gaming machines.
At least some known gaming machines include stepper motors that enable reels of the gaming machines to rotate. The rotating reels are mechanical spinning reels housed inside the machines that are spun and randomly stopped to place images, symbols, or indicia on the reels in alignment to determine payouts. Drive mechanisms for the reels have developed overtime to the point where the rotation and, in particular, the stopped position of the reels is precisely controlled to manage the allocation of payouts. More recently, electronic gaming machines have been used to simulate spinning reels using computer generated graphics and electronics. However notwithstanding the existence of electronic gaming machines, players are still attracted to, and enjoy, gaming machines having mechanical reels. These mechanical reels are typically driven by a stepper motor that enables the reels to move through a series of incremental positions and, in particular, known stop positions. Operation of the stepper motor is controlled using suitable computer processors that determine the sequence and position of the images in the reels when in the stop position and, therefore, outcomes of a game.
Although the use of the stepper motors enables fairly easy control of the position, velocity, and acceleration of the reels, the configuration of the stepper motors' direct drive (e.g., the stepper motor shaft is directly coupled to the reel's center hub) requires the rotational inertia of the reels and the stepper motors to be closely matched. Thus, when the rotational inertia changes (e.g., when the reels' mechanical design changes and/or the reels strip are made of different materials or different motion profile), the reels' rotation algorithms must be reprogrammed. Moreover, the stepper motors' direct drive must be altered with the corresponding steps that the controllers of the stepper motors take to accelerate and decelerate the reels. Therefore, without the proper stepping algorithms, the poles of the stepper motors may slip and the reels lose their position, resulting in a tilt error of the gaming machines. In addition, stepper motors are designed to maximize holding torque by holding the mechanical load at one of the steps. The holding of the mechanical load is accomplished by keeping the winding current high (even though the stepper motors' rotor is aligned with the stepper motors' stator) which wastes a lot of energy because no torque is generated unless the mechanical load tries to turn out of position.
Stepper motors are also disadvantageous because they draw substantial power regardless of load causing low efficiency, their torque drops rapidly with speed (the direction of the torque is inverse of the speed), their accuracy is low (e.g., 1:200 at full load, 1:2000 at light loads), they are prone to resonances (e.g., they require microstepping to move smoothly), they do not provide feedback to indicate missed steps, they have a low torque to inertia ratio that impedes acceleration of loads rapidly, their temperature substantially increases at high performance configurations, they do not “pick up” after momentary overload, they are audibly very noisy at moderate to high speeds, and they generate a low output power compared to their size and weight.